Stanton, Altuve, and Another Warning About Defense
Over the last calendar year, there are 139 qualified major-league hitters. Prorating their plate appearances to 600 per person, one finds that Mike Trout has the highest WAR at 7.2, followed by Russell Martin, Buster Posey, and Anthony Rizzo. None of that should come as much of a surprise, but the hitter right behind that group and just ahead of Josh Donaldson, Andrew McCutchen and Bryce Harper could provide a bit of shock. Over the last calendar year, Kevin Kiermaier has been worth six wins per 600 plate appearances.
Kiermaier, who has worked to improve his offense, is incredibly reliant on his fantastic defense for his great WAR numbers. While Kiermaier is a valuable player, it is possible that his WAR total is inflated by defensive numbers that are likely to come down over time. Kiermaier has logged roughly 1200 innings in the outfield and has a UZR/150 of 42.1, but only six active outfielders with at least 2,500 innings have a UZR/150 greater than 15, with Lorenzo Cain, Ben Zobrist, Peter Bourjos, Brett Gardner, Josh Reddick, and Jason Heyward falling between 16 and 22 — that is, roughly half Kiermaier’s current rate. Although he’s been good, Kiermaier is probably not the fifth-best player in baseball over the last year, and his defensive numbers should serve as a reminder that defensive statistics take some time before they become reliable.
Yesterday, I covered some players whose current WAR was potentially undervalued due to lower than normal defensive numbers in an article titled Heyward, Pedroia, and Your Annual Reminder About Defense. The present article renders yesterday’s title false as the articles together are now daily reminders, but this post should be the final one in this series with few, if any, more reminders coming in the near future. The caveat regarding small sample size from Mitchel Lichtman and our FanGraphs library is quoted more fully in yesterday’s piece, but to summarize: use three seasons of UZR when being conclusory about the defensive talent of any given player.